GE 90-30 PLC Switch User Manual


 
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TCP/IP Ethernet Communications User’s Manual - August 1997 GFK-1084B
Word 52 - 55 Remote PLC - Program Name (needed for access to remote %P
or %L) (zero terminated and padded)
Word 56 - 59 Remote PLC - Program Block (needed for access to remote %L)
(zero terminated and padded)
* Word 4 (CRS word address) is the only zero-based address in the Command Block.
Only this address requires subtracting 1 from the intended address.
(Words 7 –17): See the descriptions in Example 1.
(Word 18) Network Address Type: Word 18 specifies the format of the remote PLC
address. In this release, Word 18 must contain the value 1 or 3. A value of 1 indicates a
dotted-decimal IP address expressed using a separate register for each decimal digit. A
value of 3 indicates a Network Address name. See Example 1 for information on using
address type 1.
(Word 19) Network Address Length: Word 19 specifies the length in words of the remote
PLC Network Name address. With an address type of 3 specified, Word 19 must contain
32.
(Words 20-35) Network Address Name: Works 20–35 specify the Network Address
name of the remote PLC as an ASCII character string. The Network Address name may
contain up to 31 characters, is case-sensitive, and must be terminated with a null. An
error will result if the Network Address name is empty or if the name could not be
resolved into the address of an actual device.
The Network Address name must have each pair of ASCII characters reversed within the
PLC memory. For example, the name “PLC_1aa” (“P” = 50H, “L” = 4cH, “C” = 43H, “_”
= 40H, “1” = 31H, “a” = 61H, “a” = 61H ) would have 4c50H in Word 20, 4043H in Word
21, 6131H in Word 22, and 0061H in Word 23. Words 24 - 35 all contain 0000H.
Note
The Network Address name of the remote PLC must be defined in the
Name Table in this Ethernet Interface, or be defined as the Network
Address name of the remote PLC, or else be defined at a reachable DNS
Name Server. See Appendix F for more information.
(Words 36-51): Reserved, set to 0.
(Words 52 - 55) Remote PLC - Program Name: Word 52 - 55 specify the case-sensitive,
zero-terminated and padded program name (also called task name, which can be found
through the PROG Station Manager command on the server Ethernet Interface) to be
used with access to remote %P or%L memory. These words are required only for access
to such memory and will be ignored if the Memory Type field is not %P or %L. See Note
below.
(Word 56 - 59) Remote PLC - Program Block Name: Words 56 - 59 specify the case-
sensitive, zero-terminated and padded program block name (which can be found in the
program block declaration in the server ladder program) to be used with access to remote
%L memory. These words are required only for access to such memory and will be
ignored if the Memory Type field is not %P or %L.